perf.field-cls-poor

What to change

A finding of this rule on a page carries the exact edits for that page: the markup it quotes, and what to write instead.

When it runs

Runs with --field-data (fieldData), on the command and both MCP servers, and in this site's audits: it reads the Chrome UX Report's real-user data. A warning is a problem that costs a page ranking, clicks or citations. Each finding takes 5 points off the page's score.

The severity here is the rule's usual one: a finding can be raised or lowered when the page gives a reason.

Run it, or skip it

Check a page for this rule alone, after a fix for instance:

npx @rivi-software/agentic-seo-check audit https://example.com --field-data --rule perf.field-cls-poor

Or from an assistant, with the MCP tool seo_audit_page:

{
  "url": "https://example.com",
  "fieldData": true,
  "rules": [
    "perf.field-cls-poor"
  ]
}

To leave it out of an audit, pass --disable perf.field-cls-poor on the command, or disableRules: ["perf.field-cls-poor"] to a tool.

• Infoloading.render-blocking-scriptScripts in <head> load without async, defer or type="module", so the browser stops building the page until each one has downloaded and run.
• Warningloading.no-compressionThe HTML is sent uncompressed although the request accepted gzip, so every visitor and crawler downloads several times more bytes than needed.
• Warningperf.field-lcp-poorOn phones, real visits wait more than 4,000 ms for the largest element of the first screen at the 75th percentile: Largest Contentful Paint (LCP) in the Chrome UX Report's last 28 days, for the page's URL or, when it has too few visits, its origin. Google rates it poor.
• Warningperf.field-inp-poorOn phones, real visits wait more than 500 ms for the page to answer a tap or a key at the 75th percentile: Interaction to Next Paint (INP) in the Chrome UX Report's last 28 days, for the page's URL or, when it has too few visits, its origin. Google rates it poor.
• Infoperf.field-lcp-needs-improvementOn phones, real visits wait more than 2,500 ms for the largest element of the first screen at the 75th percentile: Largest Contentful Paint (LCP) in the Chrome UX Report's last 28 days, for the page's URL or, when it has too few visits, its origin. Google rates it as needing improvement.
• Infoperf.field-inp-needs-improvementOn phones, real visits wait more than 200 ms for the page to answer a tap or a key at the 75th percentile: Interaction to Next Paint (INP) in the Chrome UX Report's last 28 days, for the page's URL or, when it has too few visits, its origin. Google rates it as needing improvement.
• Infoperf.field-cls-needs-improvementOn phones, the layout of real visits shifts by more than 0.10 at the 75th percentile: Cumulative Layout Shift (CLS) in the Chrome UX Report's last 28 days, for the page's URL or, when it has too few visits, its origin. Google rates it as needing improvement.
• Warningperf.lcp-slowLargest Contentful Paint above 2.5 s (poor above 4 s). Lab measurement from Lighthouse.